Many electronic devices, such as wireless communication terminals (e.g., cellular telephones), personal digital assistants (PDAs), palmtop computers, and the like, include touch-sensitive displays that allow users to touch type on a displayed keyboard/keypad to enter information. Selection of individual keys on a display screen of a portable electronic device can be cumbersome and difficult, however. While the spatial resolution of a touch-sensitive display can be relatively high, users typically want to interact with a touch-sensitive display by touching it with a fingertip. Thus, the size of a user's fingertip limits the actual available resolution of the touch-sensitive display, which means that it can be difficult to manipulate small keyboard/keypad keys on the screen, particularly for users with large hands. Better touch resolution can be obtained by using a stylus instead of a fingertip. However, users may not want to have to use a separate instrument, such as a stylus, to interact with a touch-sensitive display.
System designers are faced with the difficult task of designing interfaces that can be used by a large number of people while also attempting to satisfy product requirements for displaying more touch-sensitive keys on diminutive displays and while achieving improved touch selection accuracy.